It is difficult to adopt voice coil motor (VCM) technology, which is typically used in conventional camera modules, for use in an ultracompact camera module, which aims at achieving low power consumption, and thus research into the technology has been actively undertaken.
A camera module mounted in a small-sized electronic product, such as a smart phone, may incorporate an autofocusing function of automatically finding the optimal focus of a lens with respect to an object.
In addition, the camera module may minutely shake due to the trembling of the user's hand while taking a photograph. Therefore, there is a high necessity for a technology capable of incorporating a handshake correction function into the camera module.
In order to fulfill the autofocusing and handshake correction functions of a lens, the camera module may incorporate a lens moving apparatus for moving a lens provided in the camera module upward and downward in the first direction and in the second and/or third direction, which are perpendicular to the first direction.
When a lens barrel in which one or multiple lenses constitute the optical system is moved in the first, second or third direction by a lens moving apparatus, the components provided in the camera module may collide with each other, and the components may be damaged or broken due to the collision.
For the purpose of precise and efficient autofocusing and handshake correction, there is a necessity to appropriately limit the distance by which a lens or a lens barrel moves in the first, second or third direction.
A conventional IT product incorporating an ultracompact digital camera is provided therein with a lens moving apparatus for fulfilling an autofocusing function of controlling the focal length of a lens by adjusting the distance between the lens and an image sensor for converting external light into a digital image or a digital video.
Autofocusing may be implemented in such a way as to measure a displacement value in the optical axis direction, that is, in the first direction, by means of a unit for detecting displacement in the optical axis direction, which is provided in the lens moving apparatus, and adjust the distance between the image sensor and the lens by means of a controller based on the measured displacement value.
Accordingly, there is a high necessity for a lens moving apparatus having a configuration capable of measuring a displacement value in the first direction and a camera module including the lens moving apparatus.